Dynamic sea surface topography

Dynamic sea surface topography is the average difference between the actual surface of the Earth and a geoid. It is caused by a steady state ocean current field in the ocean which in turn is caused by climatologic winds and temperature transport in the oceans. The dynamic sea surface topography is usually derived from ship-going measurements of temperature and salinity at depth. In recent years, satellite altimetry systems have made it possible to measure sea surface topography directly.